1. Field of the Invention
The present invention relates to radar systems. More specifically, the present invention relates to systems and methods for generating simulated radar return signals for radar testing and mode development.
2. Description of the Related Art
Modern radar systems need to be tested and calibrated under controlled conditions. One type of radar test system, often known as a target simulator, generates simulated return signals that the radar might receive in the field and applies them to the radar to test its performance.
Conventional target simulators are typically very hardware intensive. In order to simulate a single target, a conventional target simulator requires RF (radio frequency) hardware to generate or receive a radar transmit waveform, mix the transmit signal with an appropriate Doppler frequency (dependant on the simulated target's velocity relative to the radar), and add an appropriate delay (dependant on the simulated target's range). When simulating multiple targets, each target is generated separately and thus each added target needs additional RF hardware. The system can therefore become very large and expensive when several targets need to be simulated.
Furthermore, an important function of modern radars is the ability to find targets embedded in clutter (unwanted return signals from objects within the radar field of view other than the targets, such as from the ground). Conventional target simulators do not have the capability to generate targets embedded in clutter (called endo-clutter targets). They typically simulate clutter signals as a noise spectrum source separate from the targets, and then add the target signal. The targets are not embedded in the clutter spectrum. This, however, is not an accurate representation of a real world signal the radar might encounter in the field.
Hence, there is a need in the art for an improved system or method for generating simulated radar return signals having the capability to generate a large number of targets without excessive additional hardware, and to generate targets embedded in clutter.